Charles e



(No Model.)

G. E. SCRIBNER; APPARATUS FOR TELEPHONE SWITGHBQARDS. No. 587 406.

, Patented Aug. 3, 1897.

' iii 811(0)".- 6%4'273512 lj'raizzez UNIT D STATES PATENT OFFICE.

CHARLES E. SCRIBNER, OF CHICAGO, ILLINOIS, Assreuoa'ro THn W STERN ELECTRIC COMPANY, OF SAME PLACE.

APPARATUS FOR TIELEPHONE-ISIWITCHBOARIDS.

srncrrxcarron forming art of Letters'iatent No. 587,406, dated August a, 1897.

' Application filed December 18,1898. Serial Ila-616,127. lilo model.)

To all whom it. may concern:

. Be it "known that I, CHARLES E. Santana,

a citizen of the United States, residing at Chicage, in the county of Cook and State'of Illinois, have invented a certainnew and useful Improvement in Apparatus for Telephone- Switehboards, (Case N o. 434,) of which the 'following is a full, clear, concise, and exact description, reference being'had to the ac companying drawing, forming a partof this specification.

My invention concerns the signalin appliances in telephone-switchboardsfor'lines centering therein.

It consists in meansfor eflacingthesignal displayed in association with the line to indicate a call in the establishment of connection with the line. It also concerns the supervisory signals designed for temporary asso: ciation with the lines during connection with them and means for exciting these signals controlled by the telephones at substations.

5. plug s "and.the contact-pieces of the spring In certain switching systemsof well-known construction the apparatus at the. substation is so arranged that current is produced in the line during the use of the telephone; and in the switchboarda relay is provided in con nection with the line and responsive to cur-' rent in it, which controls'a subsidiarysignal associated with the'spring-jacks of the line. Further, other signals-termed supervisory signals are associated with the connectingplugs used for uniti'n g lines and controlled by other relays interposed in the conductors uniting the plugs. a

My-invention pertains to switching systems of this type and comprises means for efiacing or preventingthe display of the subsidiary line-signal, consisting of a magnet and an armature therefor, and switch-contacts adapted to interrupt the local circuit including :the subsidiary signal when the magnet is'excited,

together with a peculiar local circuit including the magnet, and normally open at separated terminals in the' spring-ja'ck's of the line which become crossed together by an inserted plug, and supervisory lamp-signalsassociat'ed with the terminal plugs and brought into local circuits through the agency of-the 'lines of the exchange.

rents while the telephone is in use. The line conductors are connected in the switchboard at the central ofllce' with the line-contacts of spring-jacks a and a and are extended through windings of the relay 1) to the poles of a battery c, which is common to the different The spring-jacksare assumed to be upon difierent sections of a multiple switchboard. '-*The armature b of the relay b with its contact b control a local circuit 3, which incl'udesa signal-lamp d, associated with. spring-jack (1., together with a sourceof current. Thislocal circuit 3 is con trolled also by switch-contacts of a relay 6,

which is included in a'portion 4 of another local circuit, which terminates in thimbles or contact-rin gs f'of the spring-jacks of the line, the relay c being constructed to break the circuit 3 when it is excited. 'The complementary portion of the latter circuit is a conductor 5, which terminates in opposing contaetpieces f in the spring-jacks; and which includes a battery 9. These parts f and f are designed to register with and be crossed to-- gether by a separate contact-piece in the plug which is used with them. The type of springjack iswell knownin the art of telephony.

The connecting-plugs 'h and-h have each a pair of line-contacts i andi, which register with the springs f and f ofthe spring-jack,- and a sleeve 3?, which crosses together. the

contact-pieces fand f of the spring-jack, a The tips 'i of the plugs arejunited by a conductor 6 and the rings t" by another conductor 7.- These conductors constitutethe plug.-

circuit. The-usual calling-key 7c is interposed in them in position to interrupt the .connec-.

tion between the two plugs and to loop a gen-,

key for p u rposes of tcsti ng, as will bun'crei naftcr described. That pole of battery which is" orator of calling-current into circuit with the 1111" 7a and the usual cratonslistenin h 7 D keyl is furnishcdto bring the operators telephone In into a bridge of t ie plug-circuit. In a permanently-closed bridge 8 of this cir: cult the source of cu'rrent 'c is contained togellier with windings o fimpedance-coils o. Ono-oi the windings u'. is includedbetween one pole of the battery and the conductor 7.

Two other windings 0 and. o are interposed.

between the battcryaud conductor 6. They are normally connected in multiple, but their multiple connection is controlled by switchcontacts I and Z'- of the operators listeningconnected with conductor 6 is also grounded.

The sleeves i of the plugs hand h constitute the terminals of grounded conductors 9 and 10, respectively, whose continuityis controlled by the switch-contacts or relays p and- The magnet of the formeripf these is in-' cluded in conductor? of the plug-circuit between the plug hand the point of connection of battery 0 with the plugecircuit.

7"between plug 71. and the battery. Hence 'eacliof the relays will-respond to current created by the battery in the plug-circuit and through the conductors of one only of. the lines'-that one with which the plug corre- 1 spending to'therelay is connected. These conductors 9 and 10 include supervisory lampsignals q and g, respectively, each of which is associated with the plug forming the ter-' minal of the conductor which includes it. The operation of these signals is as follows: The removal of the receiving-telephone from its switch at a substation permits the battery 0 to create a current in the line-circuit and through the windings of relay 1), whereby the magnet is caused to closet-he local circuit 3,;ineluding the subsidiary signal-lamp d:

. together the contact-pieces f and, f of the spring-jack, whereby they armature of the relay c is attracted and the signal-lamp (l is extinguished. At the same time the electrical condition of test-rings f of the line is altered to indicate the busy condition of the line to an operator at a distantswitchboard, the rings being raised .to a difference of potential from the earth corresponding to the elec-'.

troinotivc force of battery 9. The conductor 9, terminatiugin the sleeve 1? of the plug, also becomes connected with this batteryg in condition to pormitthe illui niuation of supervisory lamp ([5 when the break in the I Thatof I the latter is similarly included in conductor,

conductor shall be closed by relay 1?. It will be observed that this relay is'now excited by currentflowing from battery 0 through conductor 7, line conductors l and J, and 0011-.

ductor 6 of the plug-circuit, returning to but teryc 'at the central ollice. Having learned the order for the connection required, the operator makes the usual tcstot the line called for by applying the ti pi of plug h to -the test-ring fof the spring-jack of, the required line. Obviously if no connec ion exists. with that line no test-signal will be receiy'ed, since the circuit, which is completed from earth through winding a, conductor 7 to the tipof the plug, and conductor 4 to earth, includes no source of current. If, however, a connection with the line be already in ex; -istence, there will be a branch from the rings .1 through the plug, whereby the connection has been made to the contact-piece'f, and

thencc through battery 9 to earth. Then at each application of the test-plug to the testring a current will flow through the winding o 'of the.impedance-coil to earth, whereby a current will be induced in winding 0", which will circulate in the circuit including the operators telephone and will make anaudible signal therein.

1 It will be noted that the conductor 6 of the plug-circuit forms a'portion of the return circuit of curreutfronibattery 0 through the line, and hence its electrical condition will be altered by Various changes in the cony'itions of the line and its utility as a port" on ofia circuit for testing the electrical condition too of other lines would be impaired. The tunctlon of. contacts Z and l and of findings 0 and o ls to separate the portion of conductor (3, leading to the'tip of the plug, from the remainder of the plug-circuit, preserving only an inductive connection between them. Then no-ehauge in the conditions of til G circuit externalvto the portionot the lug-circuit including helix o and extending. to the tipof the plug can affect this port-ion. When the operators telephone is disconnected after a test has been made, the break in the conductor (iis closed and the windings u and o are brought into parallel circuits and act as a single helix of the impedance-coil.

- Having tested the line called for and found it free for connection, the operator inserts plug it into the spring-jack just tested and depresses the calling-key 7;. The insertion of the plug into the spring-jack brings the spring-jacks of that line into condition to test busy subsequently. It also causes the excitement of magnet e of that line to break the lamp-circuit land brings the battery 9 into 'circuit with conductor 10, including the supervisory signal q. Since no circuit-as yet existsthrough the subscribers line to the statiton called, the telephone at that station being still on its switch-hook, the. relay is inert and permits the closing of the bran in -conductor 10. Hence the supervisory larnp q" is lighted and remains in that condition until the response of the subscriber called permits the battery 0 to create a current in the line.

I While both supervisory lamps qandq re- 1 main dark, the operator may assume that the subscribers are in conversation.

become lighted, this may be taken as .indi- When both eating a signal for disconnection, after which the plugs may be removed from the springjacks and the appliances returned to their normal condition.-

My invention is defined in the following claims: v

1. The combination with a telephone-line, a

source of current in the line, and means at.

thesubstation" for determining the flow of current consequent on the use of the telephone, of a line-signal associated with the line in the central oflice and controlled by currents in the line, a relay adapted to breakthe circuit through the said signal when excited, a local circuit including said relay, and

meahsfor closing the said local circuit in-theact of making connection with the line,

whereby the line-signal is efiaeed when connection is m'adewith the line, as described 2.. The combination with a telephone-line and means for producing currentthereiii during the'use of the substation-telephone, of a re ay-in. the line-circuit at a central oflice, a

subsidiary line-signal in a local-circuit con= trolledJoy the relay, an'electromagnet control ling switch-contacts adapted to interrupt the I current through the subsidiary signal when tral otfice, a subsidiary line-signal in alocalcircuit controlled by the relay, a magnet controlling. switch-contacts adapted to interrupt the current through the subsidiary signal when the magnet is excited, a local circuit in:- cluding the magnet, said local circuit including a source of current and being interrupted at norm ally-separated contact-terminals in I the spring-jacks, one of said contacts in each spring-jack being a test-ring, and means for connecting the said contact-pieces together when a plug is inserted into any spring-jack;

' wherebythe line-signal is eiiaeed and the electrical condition of the test-rings is altered when a plug is inserted into a spring-jack, as described. y

4. The combination with a telephone-line -and means for producing current therein during the use of the-telephone, of a relay in the :line and a subsidiary signal controlled there:

by,an electromagnet controlling switch-contacts adapted to interrupt the current through the subsidiary signal, a local circuit including the said electromagnet togetherwith a source of currentnormally interrupted at separated contact-pieces in each of the springjacks, a plug adapted for insertion into the spring-jackand constructed to .eon'nectto;

gether thesaid contact-pieces and the plug-- circuit thereof, a conductor terminating in that contact-piece of the plug which registers with the said terminals of the .local circuitadaptedlto be brought into parallel with the a.

said electromagnet when the plug is in the jack, a supervisory signal in the said conductor, and a relay in the plug-circuit controlling the cu'rrentthrough the said supervisory signal in response to currents in the'line-cireuit; whereby the subsidiary line-signal is, ef-' faced the conditionof-the test-rin gs is altered,

and current is provided for exciting the supervisory signal, when the plug is inserted into a spring-jack, as described. a

' 5. The combination with a telephone-line,- aline-signal associated therewith, means for causing the display ofthe line-signal, and spring-jacks for the line each having two norwally-separated local contact-pieces, of an,

electi'oma'gnet adapted to efltace the line-signal in'a circuit connected with one of said local contaet-pieces. in each spring-jack, a

sourceof current connected to theother contact-piece in each spring-jack, a plug for making connection with the line, a contact-piece in the plug adapted to make connection with both of said local contact-pieces in the springjack, a circuit terminating in the said plugcontact, a lamp-signal in the lastanentionedv circuit, and means for controlling-the signal;

whereby the said magnet is excited andcurrent is provided for lighting the lamp when the plug .is inserted into a, spring-jack, substantially as described.- a In witness whereof I hereunto subscribe my name this 11th day of NoveinbenAtD. 189.6.

CHARLES E; SCRIBNER. Witnesses: I I

' ELLA E-DLE'R,

LUCILE RUSSELL. 

